Policy-driven industrial transformation and associated agriculture–ecology–economy nexus shifts within social–ecological system: a case of the greenest coastal province of China

A rising human impact alters landscape patterns and determines the agriculture–ecology–economy nexus (AEEN), which further threatens the sustainability of social–ecological system (SES). However, the mechanisms through which policy interventions drive AEEN evolution and regime shifts are not sufficiently elucidated. We adopted the Fujian Province, which is undergoing intensive policy interventions, rapid socioeconomic development, and ecosystem restoration, as a case study to examine SES evolution and its responses to diverse interventions. Vegetation greening enhanced carbon sequestration and reduced soil loss, while built-up area expansion rapidly occupied croplands, and aquaculture development squeezed coastal zones. Macroeconomic policies and industrial structure upgrades necessarily promote economic growth, which results in employment structure adjustments and population redistribution. The unequal urban–rural developments led to rural population loss and urban–rural resident migration; thus, the dominant role of rural residents in the employment structure for primary sector was gradually substituted by urban employment population for second and tertiary sectors. Regarding agricultural production, the sown area declined, and planting structure adjustments since 1997 led to a substantial decline in grain crop productivity. Regime shifts in nexus sectors reversed the pairwise interactions from co-benefits in the agriculture- (1978–1997) and ecology- (2017–2022) dominated phases to tradeoffs in the economy-dominated (1998–2016) phase, which were driven by compound policy interventions and historical events. Our findings are expected to enrich the understanding of AEEN interplay, SES governance, and support strategy formulations for regionally coordinated development of agriculture, ecology, and economy in Fujian and beyond.